<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

        .box{
            width: 100px;
            height: 100px;

            background-color: rebeccapurple;
            /* 相对定位，不会脱离文档流 */
            position: relative;
            /* 需要配合定位使用 */
            left: 100px;
            top: 100px;
        }

    </style>
</head>

<body>
    <div class="box">

    </div>
</body>

</html>